Where is the habeas corpus clause and what does it say?

The habeas corpus clause is written in the Constitution of, for example, a democratic country. The writ of habeas corpus states that, the Supreme Court may command an individual, government official, or anybody who holds the prisoner, to bring the said prisoner on a certain time and placeso that the Court could determine whether the custody of the prisoner is legal or not. 

Habeas corpus is actually a Latin phrase that means 'that you have the body'. Its origin is traced from the 39th clause of the Magna Carta that was signed by King John during year 1215.